1. Field of the Invention
The present disclosure relates to an organic light emitting display device capable of improving light emitting efficiency.
2. Description of the Related Art
In an organic light emitting display device, a hole and an electron are injected into an organic light emitting layer through an anode and a cathode, and are recombined in the organic light emitting layer to generate an exciton. The exciton emits energy when an excited state returns to a ground state as light.
In general, there is a difference in mobility between the hole and the electron. The mobility of the hole from the anode is greater than that of the electron from the cathode. Accordingly, due to the difference in mobility between the hole and the electron, a hole-electron charge balance is lost in the organic light emitting layer. When the hole-electron charge balance is lost, the number of electron-hole pairs that recombine is less than a total amount of electric charges injected into the organic light emitting layer, and the electric charges which are not recombined exist in the organic light emitting layer. As a result, a light emitting efficiency of the organic light emitting display device is lowered.